In the prior art, it is known to provide a method for generating a gear on a workpiece and a gear machining apparatus comprising a cutter which includes a cutting blade formed in the shape of a ring around a peripheral surface thereof and which is driven to rotate about an axis thereof, a workpiece holder which holds a workpiece in a rotatably driven manner, and a mover which moves the cutter and the workpiece relative to each other along the axial direction of the cutter, wherein a gear is formed on the peripheral surface of the workpiece by synchronizing the rotation of the workpiece with the relative movement of the cutter and the workpiece and by pressing the cutter onto the workpiece while rotating the cutter (for example, refer to patent document 1).